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Baton Rouge
Pilot Cities
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definition
Baton Rouge is situated in East Baton Rouge Parish
and is located in south-central Louisiana, on the east
bank of the Mississippi River.
Baton
Rouge has a population of 227,818, and the Baton Rouge
Metropolitan
Statistical Area
, which covers 1,588 square miles, has a population of
602,894.
Baton Rouge's Heat Island
In May 1998, the National Aeronautics and Space Administration (NASA) took aerial photos of Baton Rouge using Advanced Thermal and Land Applications Sensor aircraft data. These flyover photos represent a typical view of the city (left) and a thermal readout of metropolitan hot spots (right).
Aerial view of Baton Rouge (courtesy of NASA-Marshall Space Flight Center- Global Hydrology and Climate Center).
- select image for a larger view
In the thermal image, red and yellow areas indicate "hot spots" and generally correspond with roads and building roofs. Blue and green areas are cool and indicate water and vegetation.
The bright red areas in this image are about 149°F (65°C); the cooler areas are around 77°F (25°C). The solid blue swatch of color flowing down the left side is the Mississippi River. (These images have not been calibrated. Absolute temperatures will change after calibration, but relative temperature differences between surface types will not.)
Before determining how heat island reduction strategies impact an area, researchers need to evaluate existing surface characteristics. Aerial photos are useful for estimating the proportions of vegetative, roofed, and paved surface cover relative to the total urban surface in a city. Having this urban fabric information can help researchers simulate the meteorological and air quality impacts of heat island reduction strategies.
Surface cover data also help scientists determine an area's heat island. The Department of Energy's Lawrence Berkeley National Laboratory (LBNL) modeled Baton Rouge's near surface heat island, which represents near ground air temperatures as opposed to surface temperatures measured by thermal images.
LBNL conducted this modeling analysis over a large area, several times larger than the city center. LBNL staff determined that Baton Rouge has a relatively uniform temperature field, mostly due to its elevation and terrain features. Compared to Salt Lake City, for example, LBNL simulations indicate that Baton Rouge's heat island, which ranges from 3.6-7.2°F (2-4°C), is relatively larger and better defined, particularly at night.
Baton Rouge's Climate
Baton Rouge's climate is humid and subtropical throughout most of the year. Heavy rains and high humidity are a consequence of its coastal location. However, Baton Rouge's proximity to the coast allows maritime air from the Gulf of Mexico to alleviate summer heat and shorten winter cold spells.
Baton Rouge receives an average annual rainfall of
56.92 inches per year and has an average relative
humidity of 89% in the morning and 60% in the
afternoon. Average monthly temperatures range from
52.1°F (11°C) in January to 82°F (28°C)
in July. Based on 1961-1990 National Climatic Data
Center data, Baton Rouge has, on average, 2,690
cooling degree
days
and 1,669
heating degree
days
.
Local climate data, such as cooling and heating degree days, can help researchers estimate the potential energy savings and air quality impacts from implementing heat island reduction strategies. For example, areas with long, sunny, hot summers and high cooling degree day values, generally can achieve substantial energy savings.
Information on an area's local climate also can help
communities focus on heat island reduction activities
that best suit their regions. For example, cities with
predominantly dry climates may achieve greater benefits
from increasing vegetation than would cities in humid
climates. Dry-climate cities more effectively capture
the cooling benefits of evapotranspiration – or
evaporation of water from leaves. However, dry-climate
cities also need to consider the availability and cost
of water to maintain vegetation.